Version 0.9.9.7: Converted Milk Quantity to Float

Converted milk quantity systemwide to support floats instead of
just integers
Version 0.9.9.7: Crash on Registering Calf

Solved bug where app crashes when trying to register a calf
Version 0.9.9.7: Going back to farmer reg Activity

Users now have a previous button for going back to the farmer
registration activity from the first cow registration activity
Version 0.9.9.7: Added modified files to git

Added modified files:
   FarmerRegistrationActivity
to git
Version 0.9.9.7: Validation in farmer reg

Validation in FarmerRegistrationActivity improved:
   - At least two names for the farmer have to be entered
   - Validation done on the number of digits in the mobile number
   - An extension personnel has to be selected from the spinner
   - User informed when gps is recored
   - User informed if GPS not recorded by the time Farmer reg is
     done
Version 0.9.9.7: Validation in farmer reg

Validation in FarmerRegistrationActivity improved:
   - At least two names for the farmer have to be entered
   - Validation done on the number of digits in the mobile number
   - An extension personnel has to be selected from the spinner
   - User informed when gps is recored
   - User informed if GPS not recorded by the time Farmer reg is
     done
Version 0.9.9.7: Mobile numbers when registering SIM card

Now checking wheter the old and new mobile numbers when switching
numbers are blank